June 25, 2010

I’ve moved the ALIEN code repository to Github, it’s now at http://github.com/danielrichman/alien. I’ve also added some ALIEN 2 schematic work, and properly released the ALIEN 1 schematic and board (eagle files) under the CC BY-NC-SA 2.0 UK license. Have a look!

June 19, 2010

Further to my last post – I’ve now had some time to play with the XPLAIN board and I have successfully followed this guide http://fourwalledcubicle.com/blog/archives/508 to program the device without any external programmers: using code from the “LUFA” project you flash the on-board ATUSB with a bridge to access the XMEGA’s PDI pins; and the USB device pretends to be an AVRISPmkII. Great success!

Couple of notes:

Don’t even bother trying FLIP on linux, especially not 64bit. Compile the LUFA code on linux if you don’t have WINAVR installed, reboot to your dual boot windows, do the first half of that article (flashing the ATUSB) and then come back to linux to use avrdude and access the ATXMEGA

The article mentions that AVRDUDE doesn’t yet support PDI programming. Since then it would appear to have been implemented, however, AVRDUDE for Ubuntu 9.10 is too old to do PDI programming. You can just install the 10.04 deb. You know your AVRDUDE is too old if you get either of these

If you’re having trouble accessing the ATUSB’s bootloader, jumper pins 1 and 2 like it says, connect up the USB power, then using whatever metallic tool you have nearest to you, tap the RST (middle top) pin to one of the ground pins on the ATUSB’s header (pins 6 and 10, I believe).

Stuff like DDRB and PINB and PORTB as you knew it has been changed when using avrlibc in xmega mode: PORTB.DIR, PORTB.OUT, PORTB.IN.

PS: I attempted to restore the xplain to its funky-sound-flashy-state using the hex files that are provided by AVR, on the xplain pages, however this did not work (perhaps an oddity of avrdude). Instead, I used avrdude -U flash:r:temp.hex:i to back up the contents of its flash before I overwrote anything, and used that file to reset the xmega to its original state later.

June 16, 2010

Let the ALIEN#2 work begin… in 1 week. It’s still exam season so persuading the Physics department to lend an oscilloscope will have to wait, but while work itself isn’t taking place, I can still have the kind postman deliver funky stuff. First up is the XPLAIN evaluation board. We’re considering an XMEGA due to the need for many many UARTs and a DAC on our second flight, so before committing to having a PCB fabricated I’m going to use this thing to breadboard our flightcomputer. Oh, we’ve also got an NiM2, thanks to the people at Radiometrix who have showed their kindness yet again in donation.

May 3, 2010

ALIEN-1 was equipped with a Canon Powershot A560, which was programmed to capture a photo every 5 seconds, resulting in some 3,000 images. We’ve sorted through them and uploaded some of our favourites; they really amazed us and we hope you like them too!

The Powershot A560 has been used on several launches previously and is a tried and tested model for high-altitude imaging. As you can see it really isn’t anything special, which goes to show how good these cheap compacts really are! Technical details can be found on Canon’s website here. We plan to make large prints and possibly canvases soon.

Due to our messages being only 50 baud, the payload could only send down one telemetry string every 15 seconds. Therefore it may have originally looked as if our highest altitude was infact 33,116m, from message 10140. However having recovered the payload we’ve got the second-by-second GPS log back, and here is the log of the burst!

May 2, 2010

Hi all. First of all, I would like to say today has been really awesome – things couldn’t have gone better with our first launch. Anyway, we’re pretty tired at the moment and have got almost 3,000 pictures to organise. A big writeup will be coming, but in the meantime here’s a nice ‘sneak preview’ from ~30km altitude…

The Payload data (and an annotated decode of what it means) for the second that this photo was taken is pasted below$$A1,10210,14:12:27,52.240798,000.540368,29694,0000,07,2B42ABFF,45*15 | 14:12:27: N52.240798 E000.540368 29694M (07 satellites), Internal: 33.0'C, External: 0.5'C

Launching a weather balloon is not any old weekend botch job – it requires very careful planning. Having been roused from my slumber at 0720 BST, it is time to run the pre-launch checks, ensuring we have the following:

Balloon – check

Yagi – check

GAFFA TAPE – CHECK

Cable ties – check

Bring extra batteries – check

Top up phone – check

Sheet to put on ground

Umbrella

Cameras – check

Free lift weights (water bottles) – check

3G Dongles – check

Car chargers for everything – check

Glue gun & Glue – check

Camera-activating Ruler – to turn the camera on once it’s in the box. Requires a long thin rod, like a ruler. – check